SN74AS885
SN74AS885 is 8-BIT MAGNITUDE COMPARATORS manufactured by Texas Instruments.
description
SDAS236A
- DECEMBER 1982
- REVISED JANUARY 1995
SN54AS885 . . . JT PACKAGE SN74AS885 . . . DW OR NT PACKAGE
(TOP VIEW)
L/A 1 P < QIN 2 P > QIN 3
Q7 4 Q6 5 Q5 6 Q4 7 Q3 8 Q2 9 Q1 10 Q0 11 GND 12
24 VCC 23 PLE 22 P7 21 P6 20 P5 19 P4 18 P3 17 P2 16 P1 15 P0 14 P < QOUT 13 P > QOUT
SN54AS885 . . . FK PACKAGE (TOP VIEW)
P > QIN P < QIN L/A NC VCC PLE P7
These advanced Schottky devices are capable of performing high-speed arithmetic or logic parisons on two 8-bit binary or two’s plement words. Two fully decoded decisions about words P and Q are externally available at two outputs. These devices are fully expandable to any number of bits without external gates. To pare words of longer lengths, the P > QOUT and P < QOUT outputs of a stage handling less significant bits can be connected to the P > QIN and P < QIN inputs of the next stage handling
4 3 2 1 28 27 26
Q7 5
25 P6
Q6 6
24 P5
Q5 7
23 P4
NC 8
22 NC
Q4 9
21 P3
Q3 10
20 P2
Q2 11
19 P1
12 13 14 15 16 17 18
Q1 Q0 GND NC P > QOUT P < QOUT P0 more significant bits. The cascading paths are implemented with only a two-gate-level delay to reduce overall parison times for long words.
Two alternative methods of cascading are shown in application information.
The latch is transparent when P latch-enable
- No internal connection
(PLE) input is high; the P-input port is latched when PLE is low. This provides the designer with temporary storage for the P-data word. The enable circuitry is implemented with minimal delay times to enhance performance when cascaded for longer words. The PLE,
P, and Q data inputs utilize pnp input transistors to reduce the low-level current input requirement to typically
- 0.25 m A, which minimizes dc loading effects.
The SN54AS885 is characterized for operation over the full military temperature range of
- 55°C to 125°C. The SN74AS885 is characterized for operation from 0°C to 70°C.
PRODUCTION DATA information is current as of publication date....